I had run into the same thing a while ago. The error message is not
helpful at all, but I fixed it (with help from the elm Slack channel)
by changing the port signature from
port portName : X -> Cmd Msg
to
port portName : X -> Cmd msg
(note the lowercase `msg`, which makes it generic).
Che
Another approach could be to use SSH port forwarding, like:
ssh -L localhost:8000:localhost:8000 youru...@your.ec2.host
and access elm-reactor at http://localhost:8000 on your machine, while
the above ssh session is up. This has the advantage of not exposing
elm-reactor to the world, and it w
